For many years, petroleum has been recovered from subterranean reservoirs through the use of drilled wells and production equipment. Petroleum hydrocarbons may be produced in a variety of forms, including liquid crude oil, natural gas and light condensates. The discovery of significant offshore petroleum reserves has lead to the development of an industry dedicated to the design, manufacture and operation of sophisticated drilling and production equipment.
The production of petroleum from offshore reserves typically involves the placement of equipment on a floating structure above the subsea well. There are currently four basic floating hull forms utilized by the deepwater offshore industry: ship-shape, tension leg platforms (TLP), semi-submersibles, and spars. When utilized for the production of petroleum products, each of these types of floating structures can be regarded as a “floating production system.”
In many cases, a floating production system is designed and manufactured for a specific installation. The floating production system is sized and designed to support the maximum production from the producing field. Over time, however, as production from the field diminishes, the floating production system may only use a small fraction of its maximum capacity. In this way, the significant cost of the large-scale floating production system cannot be efficiently recovered while the system is operating at a less-than-optimal capacity. When the cost of operating the large-scale floating production system cannot be adequately offset by the declining production, the field is often abandoned.
There is, therefore, a need for a method for more cost-effectively and completely producing hydrocarbons from offshore reservoirs after a decline in the production. It is to these and other objects that the present invention is directed.